1. Technical Field of the Invention
This invention is related to automated vehicle parking garages and associated systems.
2. Background of the Related Art
Automated parking garage systems have been employed since the late 1950's utilizing crane systems, conveyors, hydraulics and pneumatics to transport and store vehicles within a parking structure. Recently, more advanced garage systems have been developed which include computer-controlled, specialized equipment for carrying vehicles to assigned parking spaces in a way similar to the way that computerized assembly lines or warehouses store and retrieve miscellaneous goods. In such assembly line and warehouse systems, a computer assigns a location for each item as it is received from its manufacturer, and robotic equipment carries each item to its assigned location. The same equipment is dispatched to the location when the item requires retrieval. Often, the items stored in a warehouse are placed on pallets to facilitate transportation and storage of the items. The use of pallets as supporting elements for the transport and storing of vehicles is also typical of more advanced automated parking garage systems.
Examples of automated parking garage systems are described in U.S. Pat. No. 5,467,561 of Takaoka, U.S. Pat. No. 5,556,246 of Broshi, U.S. Pat. No. 5,573,364 of Schneider et al., and U.S. Pat. No. 5,669,753 of Schween.
Automated parking garage systems typically utilize one of two methods to store and retrieve vehicles. A first prior art method employs pallets and assigns a separate pallet to each vehicle storage bay. In such systems, when a vehicle is to be parked or stored in a storage bay, the pallet associated with the storage bay is transported from the storage bay to the garage entrance where the vehicle is located. The vehicle is loaded onto the pallet and the pallet carrying the vehicle is transported to the storage bay where both the pallet and vehicle are stored until retrieved.
When a stored vehicle is to be retrieved, the pallet carrying the vehicle is transported from the storage bay to a garage exit. The vehicle is then unloaded from the pallet, and the pallet is transported back to the storage bay until it is needed again to store a vehicle.
Although the first prior art method accomplishes the function of transporting vehicles to and from assigned storage bays, it has significant shortcomings. A first shortcoming is the inefficient use of time when storing or retrieving a vehicle. Using the first prior art method, a driver parking a vehicle is required to idly wait while a pallet is delivered to the garage entrance from an assigned storage bay. Although garages may provide a limited pallet buffer (e.g., five pallets), it is not enough to handle the queues that may occur during periods of high volume business, such as in the morning and afternoon.
A second shortcoming is that the first prior art method of handling empty pallets impedes the throughput of the garage and fails to provide an endless, continuing and timely stream of pallets.
A further shortcoming of the first prior art automated parking method is that handling empty pallets impedes the primary purpose of an automated parking garage, that is, the storing and retrieving of vehicles. Specifically, the same equipment that is used to store and retrieve vehicles is utilized to handle empty pallets thereby promoting inefficient utilization of that equipment.
Yet another significant shortcoming of the first method is that it can only handle one vehicle and one procedure at a time. Thus, systems employing the first prior art method cannot park an incoming vehicle at the same time they are retrieving an empty pallet, and vice versa. As a result, an unacceptably long queue often forms at the entrance of such a garage during periods of high volume business.
According to the second prior art method, a single carrier module is used to service all storage bays without the use of pallets. In such systems, the module is stored at an idle position in an aisle of the garage when it is not in use. When a vehicle is to be parked or stored in a storage bay, the vehicle is loaded from an entry/exit station onto the module. The module carrying the vehicle is transported to the storage bay where the vehicle is unloaded. The empty module is transported back to the idle position while the vehicle remains stored until it is retrieved. Typically, the vehicle is loaded/unloaded to/from the module using either the vehicle's own drive system or a crane that traverses the aisles and reaches from the foundation to the roof.
When a stored vehicle is to be retrieved, the module is transported from the garage entrance to the storage bay in which the vehicle is stored. The vehicle is loaded onto the module and the module carrying the vehicle is transported to the garage exit. The vehicle is then unloaded from the module, and the empty module is transported to the garage idle position where it remains until it is needed to store or retrieve a vehicle.
Although the second prior art method eliminates the need to handle empty pallets, it has several shortcomings. Specifically, it requires excessive handling of the vehicle such as grabbing the tires in one way or another. The second prior art method also makes inefficient use of time when storing and retrieving a vehicle. Further, using the second prior art method puts vehicles at risk for being soiled during transportation (such as by oil or hydraulic fluid from the crane).
Accordingly, there is a need for an automated parking garage system that addresses the shortcomings of the prior art. Specifically, there is a need for a system that delivers a pallet to an incoming vehicle driver before or shortly after the driver's vehicle enters an automated parking garage. Further, there is a need for a system that reduces the time required to retrieve a stored vehicle. There is still a further need for a system handling empty pallets that does not utilize or otherwise impede the equipment used to store and retrieve vehicles. There is yet a further need for a garage system that provides throughput sufficient to service garage customers during periods of high volume business.